Normal Vascular Anatomy (Arteries)

Question 1

This is the first vessel that arise from the aortic arch.

Answer 1

Innominate artery (IA), also known as the braciocephalic trunk

Shortly after its origin the IA bifurcates into the right subclavian and right common carotid arteries.

Question 2

What are the major branches of the right subclavian artery (SCA)?

Answer 2

Vertebral artery

Internal mammary artery

Thyrocervical trunk

Costocervical trunk

Question 3

At what level does the right CCA bifurcates into the external and internal carotid arteries?

Answer 3

At the midcervical level, typically around the C3 to C5 level

Question 4

This is the second major vessel originating from the aortic arch.

Answer 4

Left common carotid artery

Question 5

This is usually the last branch that arises from the aortic arch.

Answer 5

Left subclavian artery

Question 6

What are the branches of the external carotid artery?

Answer 6

Superior thyroid artery
Ascending pharyngeal artery
Lingual artery
Facial artery
Occipital artery
Posterior auricular artery
Superficial temporal artery
Internal maxillary artery

Question 7

What are the extracranial segments of the internal carotid artery?

Answer 7

The first two segments: The carotid bulb and the cervical ICA

Question 8

Segment of the ICA that includes the distal 2 to 4 cm of the CCA, the bulbous dilatation at the ICA origin, and a 2- to 4- cm segment beyond the bifurcation.

Answer 8

Carotid bulb

Question 9

This segment of the ICA typically has neither narrowing or dilatations, almost never branches, and does not taoper.

Answer 9

Cervical segment

Question 10

Segment of the ICA where it enters the carotid canal in the petrous temporal bone.

Answer 10

Petrous segment

Within the temporal bone the ICA first makes an anteromedial right angle bend, then bends again as it courses cephalad to enter the cavernous sinus.

Question 11

An inconstant branch of the intrapetrous ICA that courses through the foramen lacerum and vidian canal to anatomose with branches of the ECA.

Answer 11

Vidian artery (artery of the pterygoid canal)

Question 12

This segment of the ICA exits from the carotid canal at the petrous apex and terminates at its entrance into the intracranial subarachnoid space adjacent to the anterior clinoid process.

Answer 12

Cavernous segment

Question 13

The cavernous ICA is further subdivided into 5 parts.

What are these parts?

Answer 13

Ascending cavernous portion (C5) - Extends from the endocranial opening of the carotid canal to the beginning of the first (posterio) ICA genu

Genu itself (C4), or the portion between ascending and horizontal segment

Horizontal portion (C3), lies between the posterior and anterior 90 degrees bends

Anterior genu portion (C2) - extends between the horizontal segment and remainder of the intracavernous ICA

C1 - remainder of the intracavernous ICA

Question 14

Where does the opthalmic artery arises?

Answer 14

From the anterosuperior ICA medial to the anterior clinoid process.

Question 15

Where does the posterior communicating artery arises?

Answer 15

From the posterior aspect of the intradural ICA just below the anterior choroidal artery

Question 16

What vessels comprises the circle of Will?

Answer 16

1. Two ICA
2. The horizontal (A1) segments of both anterior cerebral arteries
3. Anterior communicating artery
4. Two posterior communicating arteries
5. The horizontal (P1) segments of both posterior cerebral arteries
6. Basilar artery

Question 17

What are segments of the anterior cerebral arteries (ACA)?

Answer 17

Horizontal (A1) segment - The A1 segment extends medially from the ACA origin to its junction with the anterior communicating artery

Question 18

Where does the medial lenticulostriate arteries arise?

Answer 18

A1 segment and pass cephalad through the anterior perforated substance

These small vessels usually supply the head of the caudate nucleus and anterior limb of the internal capsule.

Question 19

This segment of the ACA includes the ACA from its junction with the ACoA to its bifurcation into the pericallosal and callosomarginal arteries.

Answer 19

A2 segment

Question 20

Recurrent artery of Heubner is a lenticulostriate branch that typically arises where?

Answer 20

From the proximal A2 segment (50% of the case)

Question 21

What are the two main terminal of the ACA branches?

Answer 21

Pericallosal and callosomarginal arteries (A3)

Question 22

The middle cerebral arteries are divided into several major segments. What are these segments?

Answer 22

Horizontal (M1) segment

Insular (M2) segment

Opercular (M3) segment

Question 23

This segment of the MCA extends laterally from its origin at the ICA bifurcation to its bifurcation or trifurcation at the sylvian fissure.

Answer 23

Horizontal (M1) segment

Question 24

The lateral lenticulostriate arteries arise from where?

Answer 24

From M1 segment

It course superiorly to supply the lentiform nucleusm as well as part of the internal capsule and caudate nucleus.

Question 25

These are the MCA branches as they emerge from the sylvian fissure and ramify over the hemispheric surface.

Answer 25

Opercular (M3) segments.

Question 26

Where does the posterior cerebral arteries originate?

Answer 26

From the basilar artery bifurcation.

Question 27

What are the major PCA segments and their branches?

Answer 27

Precommunicating (P1 or penduncular) segment

Ambient (P2) segment

Quadrigeminal (P3) segment

Question 28

Posterior thalamoperforating arteries arise from where?

Answer 28

Arise from the basilar bifurcation and P1 segments

It then pass cephalad and dorsally to supply the diencephalon (thalamus) and midbrain.

Question 29

The medial posterior choroidal artery originates where?

Answer 29

It originates either from P1 or the proximal P2 segment and runs anteromedially along the roof of the third ventricle.

It supplies the tectal (collicullar plate), part of the midbrain and posterior thalamus, pineal gland, tela choroidea of the third ventricle.

Question 30

What part of the posterior cerebral artery supplies the medial geniculate body, pulvinar, brachium of the superior colliculus, crus cerebri, and occasionally, the lateral geniculate body.

Answer 30

Premesencephalic crucral (ambient, or P2) PCA segment

Question 31

This PCA segment runs behind the midbrain within the quadrigeminal plate cistern.

Answer 31

Quadrigeminal (P3) segment

Question 32

What artery supplies the posterior one-third of the interhemispheric surface in reciprocal relationship with the ACA branches.

Answer 32

Parietooccipital artery

Question 33

This arteries supply the splenium of the corpus callosum and anastomose with their counterparts from the ACA.

Answer 33

Posterior pericallosal (splenial) arteries

Question 34

The vertebral arteries (VA) usually originate from their respective subclavian arteries.

What vertebral artery is the dominant vessels?

Right or Left?

Answer 34

Left vertebral artery (50% to 60% of cases)

Question 35

The VA course cephalad to entre the transverse forminana typically at what cervical level?

Answer 35

At C6

They ascend directly to C2 where they turn laterally, then superiorly , through the C1 vertebral foramina.

Question 36

The posterior meningeal artery (PMA) arises where?

Answer 36

It usually arise from the VA as it courses along the posterior arch of the atlas.

The PMA supplies the falx cerebelli and can become greatly enlarged with dural vascular malformations or neoplasm.

Question 37

The posterior inferior cerebellar artery (PICA) typically arises as a single trunk from the VA.

The PICA has the following five segments. What are these segments?

Answer 37

1. An anterior medullary segment in front of the medulla
2. A lateral medullary segment that courses alongside the medulla caudally to the level of CNs IX- XI
3. A tonsillomedullary segment that courses around the inferior half of the cerebellar tonsil
4. A telovelotonsillar segment in the cleft between the tela choroidea and inferior medullary velum rostrally and the superior pole of the tonsil caudally
5. Cortical or hemispheric branches

Question 38

What does the posterior inferior cerebellar artery supplies?

Answer 38

Choroid plexus of the fourth ventricle, posterolateral medulla, cerebellar tonsil, inferior vermis, and posteroinferior surface of the cerebellar hemisphere.

Question 39

What is the first major branch of the basilar artery?

Answer 39

Anterior inferior cerebellar artery

Question 40

This arteries arise near the basilar artery apex and curve posterolaterally around the pons and mesencephalon below the tentorial incisura and CNs III and IV.

Answer 40

Superior cerebellar arteries

These arteries supply the entire superior surface of the vermis and cerebellar hemispheres, as well as much of the deep cerebellar white matter and dentate nuclei.